“We are so sorry to say Kings of Leon are canceling their entire US tour due to Caleb Followill suffering from vocal issues and exhaustion,” the group said in a statement. “The band is devastated, but in order to give their fans the shows they deserve, they need to take this break.”

Before issuing that statement, however, two-thirds of the band took to Twitter to make it clear that other issues factored into the cancellation. “Not so good morning 4 me today. Ashamed & embarrassed by last nights fiasco. Can’t apologize enough, utterly gutted. A million I’m sorry’s,” wrote drummer Nathan Followill. Bassist Jared Followill was even more blunt, tweeting, “I know you guys aren’t stupid. I can’t lie. There are problems in our band bigger than not drinking enough Gatorade.”

Kings of Leon cancelled 28 dates in all; the band currently hopes to return to the stage on September 28 in Vancouver, making up for a show that was originally scheduled for September 14. Here’s hoping they can straighten out whatever ails them in the meantime.